Encryption to BCC recipients with S/MIME

Abstract

Encrypted email message structures can contain recipient information that can reveal, to any recipient, all of the other recipients of an email message. Because some recipients, such as recipients to whom the message was “blind carbon-copied”, should remain hidden from the other recipients, individual encrypted messages can be created. One encrypted message can be created for all of the recipients who are intended to be revealed, such as the recipients listed in the TO and CC fields of an email header. A second encrypted message can be created for all of the recipients of the message who are intended to be hidden, such as the recipient listed in the BCC field of an email header. Alternatively, multiple encrypted messages can be created individually for each recipient in the BCC field, if the BCC recipients are to be hidden even from other BCC recipients.

Description

FIELD OF THE INVENTION [0001] This invention relates generally to secure electronic mail messaging and, more particularly, relates to a system and method for more efficiently protecting the identity of recipients of electronic mail messages. BACKGROUND [0002] Electronic mail, or email, has become a ubiquitous element of modern communications. Many credit the explosive growth of the Internet, and internal corporate networks, to the ability of people to communicate and work together through email. In an effort to ensure that email from many different computing platforms can be seamlessly exchanged among the platforms, standards have been developed defining the structure of email messages, and the protocols and mechanisms used to transport and deliver those messages. [0003] One standard for governing the transmission of email messages is known as the Simple Mail Transfer Protocol, or SMTP. SMTP defines a series of commands that computing devices can use to transfer email messages from ...

AI Technical Summary

Benefits of technology

[0013] Embodiments of the invention allow BCC recipients of email messages to remain hidden to the other recipients of the email messages despite the use of encrypted message formats, such as S / MIME.

Problems solved by technology

However, neither SMTP nor the Internet Message Format provide protection against tampering.

Thus, a malicious user or computing device could intercept email messages, and alter their contents.

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